Not sure how to break this to you, but if you're referring to the supposed Nostradamus prediction of 9/11 that was popularly circulated soon thereafter, it's a load of crap.
Most of the stuff on the internet that seems fishy can be checked out on snopes.com, and here's this one:
http://www.snopes.com/rumors/nostradamus.aspa lot of ppl, eager to make sense of the catastrophe, gullibly lapped this up back then, incl some of my co-workers, who would not listen to reason after I showed them otherwise. These ppl also believe the Weekly World News etc (bat-faced boy, Elvis seen working at a Michigan WalMart, JFK met with aliens).